title: Preliminary observations on responses of embryonic and larval Pacific herring, Clupea pallasi, to neutral fraction biodegradation products of weathered Alaska North Slope oil.
abstract: Weathered Alaska North Slope crude oil (ANS 521) was subjected to biodegradation in vigorously stirred incubations for 14 days at 15 +/- 1 degrees C in 20/1000 salinity sterilized seawater, amended with nutrients and inoculated with a hydrocarbon-degrading microorganism (EI2V) isolated from an oil-contaminated beach in Prince William Sound, Alaska. A total of 13.7 mg/L water-soluble neutral fraction (WSF) was recovered from the incubation of weathered ANS 521. Toxicity/ teratogenicity tests were conducted with WSF recovered from the biodegradation system using embryonic and larval Pacific herring, Clupea pallasi. Exposures were begun at 4, 48, and 96 h postfertilization of herring eggs. Exposure concentrations were 1, 10, and 100% of the original concentration of WSF recovered from incubations (redissolved in 20/1000 salinity sterile seawater at 15 +/- 1 degrees C). Sterile 20/1000 salinity seawater without the addition of redissolved neutral fraction was used as a control. Significant (p < or = 0.05) embryo mortality or teratogenic responses were observed at WSF concentrations of 10 and 100%. On days 5 through 8 of embryogenesis, counts of heart contraction rates were significantly lower (p < or = 0.05) at the 100% WSF concentration for embryos exposed beginning at 4 and 48 h postfertilization. Grow-out of larvae from selected exposures was conducted. High mortality was noted in larvae exposed to the 10% WSF concentration beginning at 4 and 48 h postfertilization. Most of these larvae died 5 to 8 days after hatching when they elicited vertebral displacements at a time concurrent with the onset of feeding behavior.
authors.affiliation: U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, Gulf Breeze, Florida 32561, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Middaugh
authors.forename: M E
authors.initials: ME
authors.lastname: Shelton
authors.forename: C L
authors.initials: CL
authors.lastname: McKenney
authors.forename: G
authors.initials: G
authors.lastname: Cherr
authors.forename: P J
authors.initials: PJ
authors.lastname: Chapman
authors.forename: L A
authors.initials: LA
authors.lastname: Courtney
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D047108:Embryonic Development; D005399:Fishes / Q000196:embryology*; D007814:Larva / Q000254:growth & development; D010578:Petroleum / Q000633:toxicity*; D018675:Toxicity Tests; D014876:Water Pollution / Q000009:adverse effects*
chemical_list: D010578:Petroleum